<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style type="text/css">
        .img1{
            width: 50%;
        }
        div{
            width: 500px;
            height: 300px;
            /* background-color:rgb(255,255,0); */
            background-color:#ff0;

        }
        h1{
            /* background-color:rgba(255, 0, 0, .5); */
            background-color:#fa8e23;

        }
        h1{
            width: 50%;
            height: 50%;
        }
    </style>
</head>
<body>
    <img src="../wxy.jpeg" class="img1">
    <img src="../wxy.jpeg">
    <div>
        <h1>一级标题</h1>
    </div>
</body>
</html>